SCIENCE IN THE NEWS #2090 - Digest

By StaffThis is Sarah Long.And this is Bob Doughty with SCIENCE IN THE NEWS, a VOA Special English program about recent developments in science. Today, we tell of a discovery about blood vessels and cancer. We tell about a robot that eats food. We tell about the link between poor sleep and weight gain. And we tell why it is never too late to stop smoking.

Scientists at the Johns Hopkins University cancer center in Baltimore, Maryland have discovered what may be a new weapon against cancer. They found forty-six genes that are active in the cells of blood vessels that supply blood to cancers. The genes are not active in any other blood vessel cells.

Scientists led by Kenneth Kinzler and Bert Vogelstein made the discovery. They found that seven of the genes seem to help in the creation of new blood vessels to cancers. So, these genes may be necessary for a cancer to get more blood. Without more blood, the cancer cannot grow.Scientists say they may be able to use these genes to develop new cancer treatments. One such treatment might use drugs to prevent these genes from working. That could prevent a cancer from forming new vessels to get the blood it needs.

Another treatment might use poisons to destroy a protein produced by genes to make blood vessels. Scientists could attach the poison to a special antibody. It would search through the body to find only that protein that builds blood vessels to cancers.

It would put the poison in the protein to destroy it. Only that protein would be destroyed. Healthy tissue would not be harmed. But the cancer would not get the blood it needs to grow.

((MUSIC BRIDGE))Scientists have tried for a long time to invent a human-like machine. Devices that can operate themselves and do some things humans can do are called robots. Now, Stuart Wilkinson has invented a robot that can eat food. This food is used to produce energy that the robot needs to work. It is the first robot to be completely powered by food. It is called a gastrobot.

Mr. Wilkinson works at the American University of South Florida in Tampa. He has named his gastrobot Chew Chew. The robot has twelve legs and looks like a train. It has three parts. Each part is a meter long. Chew Chew's "stomach" is a device that uses bacteria to break down food. The bacteria, E. Coli, produce substances called enzymes, which can break down carbohydrates. The process releases electrons that are used to power a battery. In this way, chemical energy is used to produce electricity. Humans get energy from food in a similar way.The inventor says the gastrobot is only being fed sugar right now. This is because the bacteria break down almost all the sugar and produce very little waste. The only waste produced is carbon dioxide gas and water. Chew Chew can also eat vegetables. Scientists say the first versions of such a robot could be used to cut grass, for example. The robot could power itself with the grass it is cutting. Mr. Wilkinson hopes to improve the design of the robot so that it can feed itself.

In the future, scientists hope to invent robots that can produce enough energy to power a car or a train. Another idea is an underwater robot that could eat fish. Mr. Wilkinson says a gastrobot eating meat would produce the most energy. However, he says it might be dangerous to give robots their first taste of meat. They might realize that humans are meat and can be eaten too.

((MUSIC BRIDGE))You are listening to the Special English program SCIENCE IN THE NEWS on VOA. This is Sarah Long with Bob Doughty in Washington.

American research scientists have shown what appears to be a link between poor sleep and weight gain in older men. Men generally get less deep sleep as they grow older. The researchers say this could be linked to reduced levels of a hormone produced naturally by the body. They say these chemical changes could lead to the weight gain often observed in older men. The researchers say offering men treatments to sleep better could slow weight gain and other signs of aging.

The Journal of the American Medical Association published the findings. Eve Van Cauter and her research team at the University of Chicago in Illinois did the study. They examined the records of one-hundred-forty-nine men. The men were between sixteen and eighty-three years old. The information about the men came from studies done at four laboratories during the last fifteen years.The researchers compared the amount of human growth hormone produced by each man. Then they compared this with sleep measurements of the men. Special devices measured brain activity in the men while they were sleeping. The brain produces electrical waves when a person is awake or asleep.

As a person falls deeply into sleep, the brain sends out slower and larger waves. The slowest, largest waves happen during the first few hours of sleep.

The researchers found that men between the ages of thirty-six and fifty experienced less of the deepest sleep than younger men. Also, there was a decrease in growth hormone levels.

The researchers say reduced production of growth hormones has been linked to increased fat tissue and reduced muscle mass and strength.

((MUSIC BRIDGE))A new study confirms that cigarette smokers of any age reduce their risk of developing lung cancer when they stop smoking. It says those who stop before the age of thirty-five reduce their chance of lung cancer by more than ninety percent. Those who stop smoking by age fifty cut their risk of lung cancer by fifty percent. Experts say the study gives the best evidence yet that it is never too late to stop smoking.

The study also estimates the number of deaths linked to tobacco if people continue to smoke at the current rate.

It says one-thousand-million people will die in the next one-hundred years of diseases linked to smoking tobacco. That is ten times more than died of such diseases in the past one-hundred years.

Scientists at Oxford University in England did the study. The British Medical Journal published the results.Lung cancer is a leading killer of people who smoke. Tobacco also has been linked to more than twenty other diseases, including heart disease, and throat and bladder cancer.

The study shows that some lung damage from smoking cannot be repaired even if a person stops smoking early. But it found that the earlier a person stops smoking the greater the reduction in the risk of developing lung cancer. The British study found that only two percent of those who stopped by the age of thirty developed lung cancer by the age of seventy-five.

It found that ten percent of those who stopped at age sixty would die of lung cancer. The study also showed that people who continue to smoke into old age have about a sixteen percent risk of dying from the disease.The British researchers examined findings from two earlier studies of lung cancer and smoking. One was done in the Nineteen-Forties, the other about Nineteen-Ninety. The earlier study was one of the first to establish the link between smoking and lung cancer. Many people in Britain stopped smoking after the first report, greatly reducing lung cancer in the country. In Nineteen-Forty-Eight, eighty-one per cent of British men over the age of sixty smoked. In Nineteen-Eighty-Eight, twenty-one percent did.

Yet, deaths linked to tobacco are increasing because people in other countries started smoking more recently. Researchers hope the new findings will influence more smokers to stop.

This SCIENCE IN THE NEWS program was written by Frank Beardsley, Doreen Baingana, George Grow and Nancy Steinbach. It was produced by Nancy Steinbach. This is Bob Doughty.And this is Sarah Long. Join us again next week for more news about science in Special English on the Voice of America.